The main aim of this research is to examine the indicators of the quality of river belts in cities. A subsidiary aim of the study is to propose policy options and planning interventions for improving the quality of riverfront in cities. This literature review looks into other studies, articles and books done which are in line with topic making the study of the topic have a global perspective.
Waterfronts are dynamic places by nature. As an edge environment, the overlap of different communities of users and dramatically different conditions make for enormous amounts of complexity and energy. In the non-human realm, waterfronts are the interface of the aquatic and the terrestrial, the site of complex intertidal communities, the point of release for wave action, and the vehicle for many dispersal patterns. As related to human history and use, waterfronts have a long history of changing types and levels of uses, and are now coming back into potentially thriving and layered public use. Once the site of first settlements and exploration, they have long served as transportation corridors and ports, hubs of trade, travel centers, recreation venues, and much, much more. Waterfronts have been extensively used by humans for their utility in travel, trade, recreation, and general enjoyment, and have also suffered cycles of abuse and neglect from these very use patterns.
The waterfront zone is a special area which holding special characteristics as discuss in Table below.
TITTLE Special characteristics of waterfronts
Dynamic area Waterfront zone is a dynamic area with frequently changing
Biological, chemical and geological attributes.
Habitat Waterfront zone include highly productive and biologically diverse
ecosystems that offer crucial nursery habitats for many marine
Natural defense Waterfront zone features such as mangrove forests serves a
critical natural defense against natural hazards (flooding, erosion
Pollution Water ecosystems may act to reduce the impacts of pollution
moderator originating from land such as, wetlands absorbing excess nutrient
Sediments, human waste.
Types of waterfronts
A strip of land that fronts a beach.
A strip of land that fronts a lake.
A strip of land that fronts a River.
Concept of waterfront Development
Waterfront began as commerce centers, transportation hubs, manufacturing centers and commercial areas. Therefore, Waterfronts are seen as the focal point in many cities. But, due to various reasons including changing in transportation, containerization shipping and manufacturing this has led to a significant decline in waterfronts.
As related to human history and use, waterfronts have a long history of changing types and levels of uses, and are now coming back into potentially thriving and layered public use. Once the site of first settlements and exploration, they have long served as transportation corridors and ports, hubs of trade, travel centers, recreation venues, and much, much more. Waterfronts have been extensively used by humans for their utility in travel, trade, recreation, and general enjoyment, and have also suffered cycles of abuse and neglect from these very use patterns.
HISTORICAL PROGRESSION OF WATER FRONTS
COASTAL SEAPORT: Settlement and Initial Development
The development of modern North American seaports began with early European settlers. As ships were the primary mode of transportation for both goods and people, sites for ports that provided shelter from harsh weather and geological formations that allowed for convenient ship movement and docking became the center of all transportation-related activity. These port sites developed into bustling developments to sup- port shipping-related activities and served as a staging area for further movement.
INDUSTRIAL CENTER: Shipping and Manufacturing
Once established as a port city, these settlements then came to also serve as centers of shipping to export newly found resources, as well as sites of industrial manufacturing. As shipping becomes more advanced and the ships more massive in size, more elaborate docking structures and cargo storage infrastructure is constructed, often resulting in dredging the natural shoreline, and railroad infrastructure may be introduced. Culturally, these port cities also served as centers for exchange of ideas, information, and other cultural happenings
DECLINE AND DECAY: Changing Economies and Changing Land-Use
As the shipping industry moved to more reliance on the trucking industry, and industrial manufacturing became unfeasible, these large industrial waterfront developments were abandoned. The structures obsolete and the land often polluted, waterfronts became airports, parking lots, red-light districts, and the like.
Urban waterfront planning examines the different ways of experiencing and using the edges of seas, lakes or rivers and understanding their qualities for the community. The competition for waterfront space and the need for public access to the shore and the conservation of waterfront biodiversity as a natural resource have become an increasingly topical issue in urban policy. In many cases it has been seen that urban waterfront regeneration is driven by economic transition, concerns of social community environment, physical obsolescence and new recreational land and property requirements, environmental quality and sustainable development.22
There is no comprehensive theory of waterfront development and research on topic mostly over only few large projects in world cities.23
2.2.3 Types of riverfronts
This are riverfronts whose location is based on a sense of community, festivity, artistic expression, recreation and commercial bustle.
They are designed with nature and might include shore stabilization and wet land preservation.
They are made up of uniqueness and character to a place and provide a special educational experience by preserving the cultural heritage of a place.
It is composed of a dynamic space containing various activities intended to complement each other.
This is the place where community gathering activities, parks, gardens, picnic areas, walking, cycling and water related activities including boating and fishing take place.
This are located just next to the houses and create opportunities for other activities like retail, recreation and restaurants.
The type of activities located her entail fishing and boat repair.
2.2.4 The place of river belts as open spaces
It is generally perceived that most green and blue spaces, apart from urban parks and artificial channels, are “naturalistic” elements and gifts from nature.
Blue space is an urban design term for visible water. Attractive blue spaces such as waterfront parks, harbors, ports, marinas, rivers, open air streams, canals, lakes, ponds and fountains are thought to improve quality of life and help to moderate urban heat islands.
Many cities have highly industrialized waterfront zones that are built out with artificial land. Other cities have disrupted access to the sea with poorly designed seawalls and other barriers.
Rivers have often suffered a similar fate. It is common for historical rivers and streams to disappear as they are forced underground to use their land. In other cases, rivers disappear after their water has been diverted at the source to feed a city water supply. When water is flowing, it may be polluted by industrial waste or agricultural runoff.
Blue space is a valuable resource. Waterfront, riverside and canal-front areas are typically considered a city’s most attractive features when they are well designed and managed. It is common for cities to undo the mistakes of the past by converting industrial waterfronts to public space, cleaning up rivers and redesigning sea walls. (Spacey, what is blue space, 2016)
2.3 THEORETICAL PERSPECTIVE
2.3.1 FIGURE GROUND THEORY
The figure-ground theory of urban design and urban morphology is based upon the use of figure ground studies. It relates the amount of “figure” to the amount of “ground” in a figure-ground diagram, and approaches urban design as a manipulation of that relationship, as well as being a manipulation of the geometric shapes within the diagram. A figure-ground illustrates a mass-to-void relationship, and analysis of it identifies a “fabric” of urban structures. Other related theories of urban design employ different approaches. Linkage theory operates upon linkages between elements of an urban space, and manipulates those. Place theory operates upon structured systems of human needs and usage. (trancik, 1986)
A figure-ground diagram is a two-dimensional map of an urban space that shows the relationship between built and unbuilt space. As well as “fabrics”, a figure ground diagram comprises entities called pochés. A poché helps to define the voids between the buildings, and to emphasize their existence as defined objects in their own rights: spaces that are as much a part of the design as the buildings whose exteriors define them
This can also be vividly seen in waterfront developments as the rive acts as the unbuilt space or the void between buildings.
2.3.2 LINKAGE THEORY
The organization of lines that connect the parts of the city and the design of a spatial datum from these lines relate buildings to spaces. The concept of datum in spatial design is analogous to the staff in music, upon which notes are composed in an infinite number of ways. The musical staff is a constant datum, providing the composer with continuous line of reference. (trancik, 1986)Riverfronts as the cut through cities they help in linking one part of the city to the other through bridges and open blue spaces that are used for recreational activities. This riverfront also act as a source of transport when moving from one point of the city to the other using water vessel that travel on water.
2.3.3 PLACE THEORY
2.4 RIVER BELTS/FRONTS IN CITIES
River and its influence for the city Centre is quite broad topic. Therefore it is discussed in different aspects in the Lithuanian and foreigner scientists’ works of urban planning theory and history. Although there is a possibility to classify (though quite roughly) all these different points of view accordingly to the main object of the interests:
1. Functional(river as a functional cog)
2. Society(river as public, open space)
3. Ecology(river as ecological stabilizer)
4. Visibility(river as formant of visual identity)
Under the cover of the first group “functional cog”there are the scientists and urban planners who analyze river as a part of urban structure, however they bring out just the functional importance and tangible benefits. Le Corbusier, one of the pioneers of what is now called modern architecture, especially highlighted the functional importance of the river. In his opinion, river is the infrastructural object, something like liquid railway.
According Ch. Alexander, the need that people have for water is vital and profound. He wrote “…people will build places near the water because it is entirely natural; but that land immediately along the water’s edge must be preserved for common use. To this end the roads which can destroy the water edge must be kept back from it and only allowed near it when they lie at right angles to it.” (Christopher Alexander, 1977) This quote expresses importance of riverside as public, open place and space.
K. Jakovlevas-Mateckis analyses river from the ecological perspective. He claims that rivers and riversides are a part of natural frame and its carry out essential ecological compensation function. Riverside slopes and its greenery and even brushwood are like the lungs of the city and it encourages formation of horizontal and vertical air flow. This process ensures clean air flow and polluted air displacement into the upper layers of the atmosphere. The riverside buffer, where, according to the laws of Lithuania, urbanization is not allowed, should be left unbuilt and the width of it should not be narrowed. During the process of shaping the urban environment, closer attention should be paid for the river identity enhancement, visual quality significance, improvement of the access to the water and increase of recreation opportunities for the urban community (Mateckis, 2006)
River, as one of the most relevant factors for the visual identity, is touched in many of the studies that deal with peculiarities of settlements.
2.4.1 INDICATORS OF QUALITY
Riverfront quality are gauged with the quality of water found in the river .According to the Colorado River Watch Network (CRWN) volunteers test for several key water quality indicators. The resulting water quality data provide baseline information, helps identify trends or changes in water quality and aids investigations into problems such as nonpoint-source pollution and nutrient enrichment.
These are the key water-quality indicators:
Dissolved oxygen (DO)
The DO test measures the amount of oxygen dissolved in the water. Oxygen is essential for both plants and animals, but high levels in water can be harmful to fish and other aquatic organisms. Nonpoint-source pollution can decrease the amount of dissolved oxygen in water, which can be harmful to fish and other aquatic organisms. The decomposition of leaf litter, grass clippings, sewage and runoff from feedlots decreases DO readings. Dissolved oxygen is measured in milligrams per liter (mg/L). Expected levels: 4.0 to 12.0 mg/L
Aquatic organisms are dependent on certain temperature ranges for optimal health. Temperature affects many other parameters in water, including dissolved oxygen, types of plants and animals present and the susceptibility of organisms to parasites, pollution and disease. Causes of temperature change in water include weather conditions, shade and discharges from urban sources or groundwater inflows. Temperature is measured in degrees Celsius (°C). Seasonal trends: May to October: 22 to 35°C, November to April: 2 to 27°C
A pH test measures the alkalinity or acidity of water. A pH of 7 is neutral, below 7 is acidic and above 7 is basic or alkaline. Acid rain, from auto exhaust or other pollutants, causes a drop in the pH. Pollution from accidental spills, agricultural runoff and sewer overflows can also change the pH. Buffering capacity is water’s ability to resist changes in pH, and is critical to the survival of aquatic life. The limestone soils of Central Texas act to neutralize these acids and often result in a more basic pH. While young fish and insect larvae are sensitive to a low pH (acid), extreme values on either end of the scale can be lethal to most organisms. Expected levels: 6.5 to 9.0
Escherichia coli (E. coli)
E. coli is a fecal coliform bacteria that comes from human and animal waste. The Environmental Protection Agency uses E. coli measurements to determine whether fresh water is safe for recreation. Disease-causing bacteria, viruses and protozoans may be present in water that has elevated levels of E. coli. Levels of E. coli can increase during flooding. E. coli is measured in number of colony forming units. The EPA water quality standard for E. coli bacteria is 394 colony forming units per 100 mL.
The specific conductance test measures the ability of water to pass an electrical current. Conductivity in water is affected by inorganic dissolved solids such as chloride, sulfate, sodium, calcium and others. Conductivity in streams and rivers is affected by the geology of the area through which the water flows. Streams that run through granite bedrock will have lower conductivity, and those that flow through limestone and clay will have higher conductivity. High conductance readings also can come from industrial pollution or urban runoff, such as water flowing from streets, buildings and parking lots. Extended dry periods and low flow conditions also contribute to higher conductance. Organic compounds, such as oil, do not conduct electrical current very well, so an oil spill tends to lower the conductivity of the water. Temperature also affects conductivity; warm water has a higher conductivity. Specific conductance is measured in microsegments per centimeter (µS/cm). Expected levels: 300 to 700 µS/cm in most of the Colorado River watershed; higher near San Saba and the coast.
Nitrogen is a nutrient necessary for growth of all living organisms. The CRWN nitrogen tests measure nitrate (NO3-N). Excessive amounts of nitrates increase algae growth. Algae can rob the water of dissolved oxygen and eventually kill fish and other aquatic life. Sources of nitrates may include human and animal wastes, industrial pollutants and nonpoint-source runoff from heavily fertilized croplands and lawns. Under certain conditions, high levels of nitrates (10 mg/L or more) in drinking water can be toxic to humans. High levels of nitrates in drinking water have been linked to serious illness and even death in infants. Nitrates are measured in milligrams per liter (mg/L). Expected levels: less than 1.0mg/L.
Transparency measures how far light can penetrate a body of water. Sunlight provides the energy for photosynthesis and determines the depth at which algae and other plants can grow, defining the ecological make-up of a water body. A change in water clarity may be noticed after heavy rains, as silt and debris can run off, causing the visibility to decrease. Transparency usually decreases in the summer when plankton, silt and organic matter are more likely to be prevalent. CRWN uses Secchi disks and transparency tubes to measure transparency.
Monitors also record physical observations of water. Volunteers record water clarity and presence of plants and other aquatic life. They also may report the amount of rainfall received in the area.
2.4.2VALUES AND BENEFITS
Waterfront foster economic growth this is due to the different activities taking place due to the presence of a water front. Different services will be required order to cater for the people therefore this will boost commercial activities.
The view of the water front offers a good view for people therefore restaurants and hotels capitalize on this aspect of the water front. Many cities have capitalized on this aspect as tourism has helped them acquire capital from these water front in cities .Land along waterfronts is considered really valuable therefore making the rates of these hotel and restaurants have high rates.
The basic argument is that ports expand the market opportunity of both national and international firms. By expanding the market areas of firms, ports increase competition, resulting in lower prices for the consumers of the port traffic. These involve all sectors of economic activity, including manufacturing firms, heavy industries, resource extraction industries or retailers. Therefore, the economic benefits of ports are specific to the nature of the hinterland they service. They can be straightforward for hinterlands heavily dependent on resources, since the output is directly handled by the port, or more nuanced when the hinterland is involving manufacturing firms producing intermediate goods.
2.4.3 RIVER FRONT AND URBAN DEVELOPMENT
PLUS MANGEMENT OF INTERFACE
2.4.4 sustanability of river fronts in cities
2.5Improvin quality of riverfronts in cities
2.5.1 Theoretical oriented proposal
2.5.2Policy oriented proposal and strategies
2.5.3 design oriented